Courteney Cox on Working with Johnny McDaid: 'I Couldn't Be Happier'

Courteney Cox and musician boyfriend Johnny McDaid are more than a perfectly cute pair. They also collaborated on Cox's new film, Just Before I Go, which she directed.

The Snow Patrol rocker, 37, earned major boyfriend points for contributing to his leading lady's soundtrack.

"I've had a lot more support from him than him just being here tonight," Cox, 49, told PEOPLE at the film's premiere Thursday at the Tribeca Film Festival in New York City. "Snow Patrol wrote three original songs for this movie. I'm really fortunate. It's amazing, all the musical things that he brought to it."

Of his contributions, she added: "I couldn't be happier. It really elevates the film in so many ways."

McDaid wasn't the only friend Cox recruited for her feature-film directorial debut. Gabriel Cowan, an old pal of the Friends alum (and her very amicable ex, David Arquette), produced the film – and he's a Snow Patrol fan, too.

"[Johnny] has become a great friend," Cowan told PEOPLE. "He's a good guy, and his friends are good people. He's just a solid guy: He's got a very strong energy, and he's filled with heart."

And Cox even keeps it in the family, as daughter Coco, 9, made a cameo in the picture, too.

After the screening, the actress-director made a night of it with friends, family, costars, some Bombay Sapphire gin (for good measure) – and her boyfriend, obviously. McDaid and bandmate Gary Lightbody took the stage at the Flatiron Room afterparty for a special performance, which included songs from the film as well as their crowd-pleasing throwback "Chasing Cars."

"It was Courteney's night, but she wanted to cheer on her boyfriend," an onlooker tells PEOPLE. "She was swatting cameras away and told everyone in the crowd to quiet down – she was really adamant about hearing her boyfriend."

"She was standing front-row, singing and dancing along to their whole set."